When servicing luxury motor vehicles, mechanics must take great care not to damage the exterior finish of the vehicle. The exterior finish of the vehicle is susceptible to scratching, if the mechanic lays his tools upon the vehicle or rubs the fasteners on his overalls against the finish or while leaning against the automobile inadvertently causes any hard particle in any way to be pressed against or moved along the paint surface. The exterior finish is susceptible to dents if subjected to an impact from a dropped tool or the weight of a heavy object. The exterior finish is susceptible to corrosion if exposed to the chemicals present in brake fluid, carburetor and brake cleaners, and other substances used by the mechanic in the process of servicing a vehicle.
In order to avoid such damage, protective fender covers are commonly used. These fender covers are made from a variety of materials arranged in permanently conjoined layer, and include covers with a cloth top layer with a cloth backing layer, a vinyl top layer with a vinyl backing layer, a vinyl top layer with a rubberized back layer, a vinyl top layer with a cloth backing layer. Some mechanics have discontinued using protective fender covers due to experiences in which the protective fender covers were found to contribute to, rather than prevent, damage. Covers having a cloth top layer with a cloth backing layer have an advantage of being washable. The disadvantages associated with such covers is that they do not stay in position on the fender, liquid contaminants soak through to the fender, they tear easily, they provide negligible impact protection, and if not washed frequently can carry contaminants from one vehicle to another. Covers having a vinyl top layer with a vinyl backing layer provide a number of advantages; they are durable, they can be wiped clean of contaminants between uses, they can provide a greater degree of impact protection, and they do not allow liquid contaminants to soak through. A primary disadvantage associated with such covers is that the vinyl back tends to compress dust or dirt particles against the exterior finish, thereby causing microscratches when shifting of the cover relative to the fender occurs. This is especially pronounced with softer "clearcoat" finishes most commonly found on modern luxury vehicles. Covers having a vinyl top layer with a rubberized back layer have an advantage of improved impact protection. The primary disadvantage associated with such covers is that embedded particles and liquid contaminants tend to remain in the rubberized backing layer as it can't readily be washed or wiped clean. These covers can also leave black marks on the paint and have a relatively short life span. Covers having a vinyl top layer with a cloth backing layer attempt to combine the advantages of each. This has not proven to be successful. The cloth backing layer can not be wiped clean and is difficult to wash properly due to the attached vinyl top layer. Particles embedded in the cloth layer accumulate until the surface approaches a texture similar to that of sandpaper.